Night Flap

Cinevva's analyzer read this game's design doc and its source, then wrote the brief below. "Make your own" hands it to the game creator as your opening message, so you start from a real spec rather than a one-line idea.

Create a portrait, full-screen mobile arcade game titled “Night Flap,” a Flappy Bird-style one-button game built on a continuously animated HTML canvas. The player controls a tiny green duck/bird flying at a fixed horizontal position around 28% of the screen width. The duck is a 42px character sprite, with a soft green glow beneath it; use a pixel-art green duck sprite if available, and a simple green circular duck with white eye and orange beak as fallback. The bird rotates smoothly based on vertical velocity: nose-up while rising and nose-down while falling, with a small squash/stretch flap animation.

Core gameplay: begin at a centered menu overlay with title “Night Flap,” subtitle “Tap to flap through the dark peaks,” a Play button, an optional saved “Best · N” line, and bottom hint “Tap anywhere to start.” Tapping/clicking anywhere, pressing Space, ArrowUp, or Enter starts the run. The same inputs during play apply an upward flap impulse. Physics should use gravity around 980 px/s² and flap velocity around -340 px/s, with a brief start grace period so the player is not immediately hit. The bird falls continuously between taps. The world scrolls from right to left: generate vertical pairs of deep indigo/violet pipes, each 64px wide, with a gap initially about 240px tall, narrowing gradually by up to 70px as score rises but never becoming unfair on short screens. Pipe pairs are spaced about 260px apart and move around 145px/s, increasing by roughly 2.2px/s per point up to a 70px increase. Randomize each opening vertically within margins around 10% of screen height. The player must fly through openings without touching a pipe, the top edge, or the ground. Use a forgiving square collision hitbox about 55% of the bird size.

Award one point whenever a pipe pair fully passes the bird. Display the score as a large centered white/lavender number near the top, with dark shadow and violet glow; animate a brief scale pop on each point. Every tenth point, add a celebratory particle burst and a subtle screen flash. Save the best score in localStorage under “nightFlapBest.” On collision, enter a dead state, play a brief pale flash, emit particles, play a light impact sound, and allow the bird to fall to the ground. After roughly 650ms show the game-over overlay: title “Crashed,” subtitle “You scored N” and an achievement suffix based on score (10+ Bronze, 20+ Silver, 30+ Gold, 40+ Platinum), button label “Again,” hint “Tap anywhere to retry,” and show “New best · N!” when a new record was achieved. Restart only after the short post-death lock.

Visual setting: a stylized dreamy nighttime sky with a very dark indigo/purple upper background transitioning toward violet, pink, and soft rose near the low horizon, plus a subtle horizon bloom. Add a large glowing pale moon near 78% screen width and 14% screen height, with a small translucent crater. Scatter around 70 small twinkling pale stars across the upper 55% of the sky. Add a few slow-moving semi-transparent purple-tinted clouds using cloud sprites when available. Behind the gameplay, create looping parallax mountain layers: distant wide dark-purple angular silhouettes moving slowly and nearer jagged pointed peaks in deeper indigo/violet moving faster. Give peaks subtle cool snow/highlight caps and overlay faint fog toward their bases. At the bottom, draw a fixed 72px-high dark ground band with a thin lavender top edge and repeating muted purple rectangular dash details that scroll horizontally. Keep the pipes visually integrated into the night palette: dark indigo bodies with subtle horizontal shading, violet/lavender rims and caps, vertical highlights, rounded cap corners, and faint lavender lines at the edges of the gap.

Use a clean rounded bold sans-serif UI style similar to Nunito. Menu and game-over overlays should be centered with a translucent dark radial scrim. The title is large pale lavender with purple shadow and glow. The Play/Again button is a large rounded pill with a pale-pink-to-bright-pink vertical gradient, dark text, darker pink lower shadow, and pressed-down active state. Make the entire screen touch-friendly, prevent scrolling and text selection, support pointer/touch input and keyboard input, resize responsively for portrait mobile and desktop windows, cap device pixel ratio at 2, and keep the game canvas full-screen behind the HUD. Include flap, score, impact, and looping quiet background audio if assets are available, starting audio only after user interaction. Add small colored particle bursts for flaps, impacts, and milestone scores.